Method and means fob selecting balancing networks



May 25 1926. 1,585,770

R. D. CONWAY METHOD AND MEANS FOR SELECTING BALANCING NETWORKS FiledDec. 5. 1921 3 Sheets-$heet 1 /n venfor: E0] [7. Conway May 25,1926. 1,585,770

R. D. CONWAY METHOD AND MEANS FOR SELECTING BALANCING NE' l-WORKS Filed Dec. 5. 1921 3 Sheets-Sheet 2 .1

May 25 1926-. 1,585,770

' R. D. CONWAY METHOD AND MEANS FOR SELECTING BALANCING NETWORKS Filed Dec. 5, 1921 5 Sheets-Sheet 5 M er? for: a [2 Canal/a b] My Patented 2P5,

UNITED STATFEEE PATENT OFFICE.

ROY D. CONWAY, OF CHATHAM, NE'W JERSEY, ASSIGNOR TO VZESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEXV YORK, N. Y., A CORPORATION CF NEW YORK.

METHOD AND MEANS F03 SELECTING BALANCING- NETWORKS.

Application filed December 5, 1921.

This invention relates to the selection and connection of balancing networks in repeat ing circuits and aims to make the requisite number of networks for handling tratlic as small a number as possible by providing for the connection of any network to any repeater and to any line with which any of the repeaters is used and which the network, alone or in combination with others of the networks, is capable of balancing.

The invention also aims to provide for automatic or semiautomatic selection and connection of the networks by means includ ing across-bar switch.

Other objects of the invention will be ap parent from the detailed description hereina'lter of the accompanying drawing illustrating the preferred embodiment of the invention.

In the illustrative system disclosed hereiuafter employing the invention applied to operators cord circuits, there is provided a plurality of sets of networks, each of which sets may comprise a plurality of types of networks such as basic networks, build ing out sections, and balancing sets. And means including the cross-bar switch operates in response to the connection of two lines by a repeater cord circuit to select the proper basic networks, building out sections and balancingsets for the connected lines and to connect these various balancing networks to the repeater. The system is such that any idle network may be so selected and connected to any one of the plurality 0t lines which may require a balancing net w-crl; of the type of said idle net-work, and yet any one of a number of repeater cord circuits may be used in connecting the line with other lines. Thus, it is not necessary to provide a. complete set of networks for each one of the repeater cords, but is only necessary to equip the system with such a number of networks of each type as may be required to be used at the same time. The illustrative system disclosed also provides for taking care of an overflow or unusual lemand tor a certain type oi net work by having lamps for indicating the type oi network required and the repeater cord on which it is required, and having cord cir cuits embodying variable impedances which the ooerator connects to the cord which one the lamps has indicated as requiring a l l10t3.-1i-I and ad, to term a.

Serial No. 519,864.

network of the type which one of the lamps has indicated is required. Further, lamps connected to sleeve conductors of the cord circuits embodying the variable impedances indicate to the operator when the repeater cord circuits are no longer in use and the impedances are no longer required.

In the accompanying drawing Figs. 1, 2 and 3, when arranged one above the other in the order mentioned with Fig. 1 at the top, show diagrammatically a preferred form of the system embodying the invention in its application to operators repeater link circuits. Fig. 4 is a perspective view of a part of a cross-bar switch which may be employed in the invention.

This cross-bar switch is of the general type disclosed in United States Patent to J. N. leynolds 1,238,194, August 28, 1917, entitled Automatic switch. This switch comprises vertical bars such as 1 shown in Fig. l and shown diagrammatically in Fig. 3, and comhorizontal bars such as 2 shown in a and shown diagrammatically in Fig.

0. For reasons which will be made apparent hereinafter, the vertical bars may with propriety be hereinafter termed cord bars and the horizontal bars may appropriately be hereinafter termed net bars. Each of these vertical bars comprises a plurality of vertical metallic strip conducting members having: projecting spring contacts such as those designated 3 in Fig. 4c, and each of the horizontal bars comprises horizontal metallic strip conducting members having contact projections such as those designated 41: in i i l. The vertical bars are mounted in the frame (not shown) oi the cross-bar switch by means of vertical pivots such as 5; Each horizontal bar 2 is supported from the frame (not shown) of the crossbar switch by means of members 6. rigidly attached to the frame, and link 7. The link 7 is pivoted to members 6 by pin 8 and to bar 2 by pin 9. The spring 10 normally presses the bar 2 lengthwise toward the right as viewed in Fig {1-, but the bar 2 may be moved lengthwise toward the left as viewed in Fig. 4 by armature 11 of electromagnet 12 when the electromagnet is energized. This armature is in the form of a bell crank lever pivoted at 13 in the frame of the cross-bar switch and bearing against the pin 9. A spring 14. normally biases the bar 1 in a counter clock 4. Upon the energization of the electromagnet 15, the armature 16 thereof overcomes the biasing action of spring 14. The armature 16 is mounted in the frame of the crossbar switch by a pivot 17.

In the operation of the switch, magnet 15 turns bar 1 clockwise to position spring con tacts 3 for subsequent engagement of their ends by contact projections at, and magnet- 12 moves bar 2 lengthwise to engage contact projections i with that set of contacts 3 lo cated at the intersection of bars 1 and 2. Upon the deenergization of magnet 15, spring 1e turns bar 1 counter-clockwise looking down upon Fig. l, to restore bar 1 to a position in which the ends of all of its sets of contacts 3 except the engaged set are out of the line of movement of contacts such. as 4.

Bar 1 carries a strip 18 of insulating new terial on which are mounted conducting plates 19 for bridging across contacts 3. lVhen contacts i engage spring contacts 3, the latter are moved out of engagement with plates 19. The purpose of providing bridging plates 19, and the manner in which magnets 15 and 12 are energized will be made apparent hereinafter.

The magnets, such as 15, which actuate the vertical or cord bars may be termed cord bar magnets, and the magnets, such as 12, which control the horizontal or net bars may be termed net bar magnets. it will be explained below that each of the net bar magnets comprises two magnets, a net bar pick up magnet and a net bar locking magnet.

in the diagrammatic showing of the crossbar switchin Fig. 3, the net bars are desig nated 2, 2, 2", 2, 2 etc, reading from the top of the figure to the bottom of the figure, and the cord bars are designated 1, 1, 1 1, reading from right to left. In Fig. 3, the spring contacts of cord bar -1, generally considcrcd, are designated 3, those of cord bar 1, generally considered, being designated 3", those ot cord bar 1", generally considered, being designated 8, etc. Certain ones of these spring contacts are, for convenience, designated by various reference characters individual to the spring contacts to which they are applied. The contact projections of net bar 2, generally considered, are designated 4E, thoseof not bar 2*, generally considered, being ccsignated 49, those of net bar 2, generally considered, being designated 42, etc. (ertain ones of these contact projections are, for convenience, designated by various reference characters individual to the contact projections to which they are applied.

Referring to Fig. 1, repeaters such as R and R, which may be oi? any suitable type such as the well-known vacuum tube repeaters, are employed to interconnect lines such as L L L and L Referring to Fig. 3, networks for balancing these lines are shown at 21, 22, 2a, 24, 25,26 and 27. Networks 21,.22 and 23 may be building out sec tions or may be balancing sets for composite or phantom apparatus. Networks 24L and 25 may be building out sections or may be basic networks. Networks 26 and 27 may be for instance, basic networks having impedanccs different from those of networks 24: and As appears from Fig. 3, each of the net bars of the crossbar switch has connected thereto one of the networks 21 to 27. It will be un- 7 derstood, of course, that the drawing does not show all the cord bars or net bars and networks which may be included in a single cross-bar switch.

The operation of the system in selecting suitable balancing networks and connecting them to the lines L, and L, will now be described, on thesupposition that the operator inserts plugs P and P into the jacks of line L, and L, to connect these lines through repeater R. Upon the insert-ion ct plug l in the jack of line L magnet 30 is ener gized by current flowing in the circuit from ground through battery 31, resistance magnet 30, lead 33, sleeve conductors of plug s- P and the cooperating jack, lead and magnet back to ground. Magnet 30 attracts its armature, but the closing or this contact does not complete any circuit. Magnet 35 does not attract its armatures at this time, because the resistance 32 reduces the current flow from battery .31. Upon the insertion of plug P into the jack oi line 11,, magnet 36 is energized over the tollowin'" circuit: from ground through batt 7 53?, resistance 88, magnet 35, lead 39, sleeve conductors 0t plug 1? and the cooperating jac lead 40, magnet ll back to ground net 41 does not attract its armatures at this time, because the resistance 38 reruccs tluv current flow from battery 37. The in net 36 attracts its armature closing a circuit for magnet l2 as follows: from ground thro 'gh battery 43, armature a l of magnet lf, lead 46, lead 47, contact spring -l-8 of h lead 50, armature 51 of magnet 36., ion arn'iatnre 53 of magnet 30, lead 54:, c ntact spring 55 of magnet 56, lead lead 58, lead 59, armature ct ma and lead 62 to ground. Each of too i 45, 4:2 and 6], is individual. to a repeats circuit, magnets 47 and. (it being operat-M. the same fashion as magnet 42. Only one o these magnets can be in the operated co .l'z tion at any given time, as will be reiulily an parent from the arrangement of the armatures of these magnets in the battery lead it; and ground leads 59 and as shown in tidrawing. There will of course be one ma net such as the magnets e5, and (ii each repeater cord circuit. It will be made apparent hereinafter that since only one of the magnets can be in the operated condition at any given time the operation of selecting balancing networks and connecting then: to

will be finished betnre such operation 'an begin for a other repeater.

has been energ ied 114 iii;

i ures (3.3, c ion control relay 11 to attract its arnati Ell, 10% and 11.22. This operati c n of -11 are to the energization of this n over the following circuit: from ground through bat ery 13, armature 12, lo d 10, armature oi-l, lea-(l (38. lead (37, armature ($8 of retarded relay T0, armature (i3, ieac T1, magne' so.

69, lead 1 lead 3? sleeve conductors of plug i" and the coopera ing jack, lead 10 and magnet -15. to ground.

The attrac ion of armature til of relay -15. as mentioned above also causes the cord bar magnet 15, which is lilLO the co -d bar magnet 15, shown in Figs. 3 and 1, to attract its armatures 16*, T2 and '3, the. circuit for c "sing this cord bar ing as i from ground throng t 1' 13, a. atl. 'e ell, lead l0, armature (5-1, lead tt, lead (ii, lead 7-1, lead 75, arn'iature 7a or retardei relay 19, lead 77, lead 78, cord bar nagnet 15 to ground. The attraction oi he armature by cord bar magnet auses the cord bar 1 to turn on its pivots 0 position its spring contacts 3 for subseengagement of their ends by contacts of a not bar in the fashion described above in connection vith Fig. l.

The attraction of armature :3 by magnet 15, and the attraction 0'1 armature 9t 0? line selection control rel-a3 all, both as mentioned ibove, causes the oper: t-ion of magnets T0 and 80 over the following cirzuit: from ground through battery 1 3, armature l i (ll, cad on, leads 6?, 1 and 75, armature 76, leads 7T ant 81, mi iet 70, lead armature 73, lead 8 lead 81-, lead 85, arn'iature 80, contact spring 84', not bar pick-up magnet 80, lead contact spring 80, armature 00, lead 91, lead 02, lead 93. and armature 91 of line selection control relay 11 to ground. The net bar pick-up magnet 80 forms part of the net bar magnet 12, shown in Fig. 1 and also in Fig. 53, each net bar magnet comprising in addition to a pick-up magnet, a locking magnet such is shown at ill in Fig. 3. llpon tin energization of the pick-up magnet 80 of magnet 12, as just mentioned, the not bar 2 is moved longitudinall toward the left to engage contact projections 150, 119, etc., vith contact springs 1.38, 118. eitci, (these projections and springs being locat d at the intersection oi bars :2 and 1'). all in the general jiashioi des'ribcd aoove in con net-lion witl Fig. -l.

The attraction 01 ari'nature 73 by cord bar uagnet l5 and the attraction of armature 10lh line selection control relay 11, both .s mentioned above, auses the operation oi iet bar piclnup magnet 05, the energizing circuit for this magnet being from battery l to lead 81 as just traced and thence through lead on, armature 07, contact spring 98, magnet 95, contact spring 00, L; ature 110, lead 101. lead 102, lead 103, a 1

r l rriature ground. Thereupon the not bar 3" is d to engage contact projections 1723, etc, with contact springs 172, 12-1, etc. the attraction of armature T3 of magnet and the attraction of armature 113 of c selection control relay 11, both as 1nen toned above, :auscs tho ope -ati0n 01 not bar pict-up ma not 105, the energizing circuit tor this magnet being from battery 413 to lead as traced abo e and thence through lead 106, armature 10?, con act spring 108, net bar pick-up magnet. 105, armature 109, armature 110, lead 111, lead 112 and armature 11?? to ground. 'ihereupon the net bar 2" is moved to engage contact projections rats, 131, etc. with contact springs 185, 130,

etc.

The energization (it not bar pick-up magoriginal energizing circuit, or pick-up cir cuit, which passed through magnets 79 and 80. However, before such circuit is broken, armature 80 allows contact spring 87 t0 com-act with a ter ninal ot the coil of magnet 11%. and armature 90 allows contact spring til) to contact with lead,12i2, and moreover, contact 119 has engaged contact 118, as mentioned above; and, therefore, a locking circuit, including the pick-up magnet 80 and the locking magnet 11 1 in series, is closed for net ba' magnet 12, this locking circuit being as follows:

' ground through battery 13, armature ll, lead -16, armature 6%, leads 06, (3"? and 7-1, armature of magnet 79, leads 115 and 110, cord ba' conducting member 111', cord bar contact 11?, net bar contact 119, not bar conducting member 120, lead 12 1, net bar locking magnet i ll, armature 87, net bar pick-up magnet 80, lead 88, armature 89, lead 122 to groui'id. As soon as armature 80 has become disengaged from contact spring 87 (and armaturcs 97 and 107 have similarly and simultaneously disengaged 'outacts 08 and 108, due to the energization, as mentioned above, oi magnets 95 and 105), magnet is deenergized and therefore the circuit just traced from lead 71 to lead 116 is brolzcu at the armature of magnet 79: but a locking circuit for not bar magnet 12 is inaintaiuci'l, tor a circuit from lead to lead ll is mainta ned through the followbetween lead H and lead 116:

112g pa From lead 71 through lead and resistance 135 to lead 116. Moreover, a new circuit between lead 74 and lead 116 1s established through the back contact of the an ature of magnet 7 9 and the Winding of mag net 69.

The .iergization of net bar pick-up magnet 95, as mentioned above, results in the establishing of a locking circuit for 1nagnets 95 and 1.2 :5 just as, in the manner described above, the energization of not bar pick-up magnet 80 results in the establislr ing of a locking circuit for magnets 80 and 1. L. The locking circuit for magnets 95 and 1. .5 is as follows: from battery 43 to cord bar conducting member 11?, as in the case of the locking circuit for magnets 80 and 114, thence through cord bar contact spring 124, not bar contact projection 125, net bar conducting member 126, lead 27, magnet .23, contact spring 98, magnet 95, Contact s1 ing 99, lead 128, to ground.

The energization of net bar pick-up magnet 105, as mentioned above, results in the establishing of a locking circuit for magnets 95 and 123 just as, in the manner described above, the energizat-ion of net bar piclcup magnet 80 results in the establishing of a locking circuit for magnets 80 and 114. The locking circuit for magnets 105 and 129 is follows: from battery 43 to cord bar conducting member 117, as in the case of the locking circuit for magnets 89 and 11.4, thence through cord bar contact spring 130, net bar contact projection 131, net bar conducting member 132, lead 133, magnet 129, contact spring 19, magnet 105, contact sprin 109, lead 134 to ground.

As has been mentioned above, the energization of not bar pick-up magnets 80, 95 and 105, causes the deener tion of magnet 79 by opening branches of the circuit for magnet 79 at armature S6 and contact 8?", armature 97 and contact 98, and armature and contact 108, and the armature of magnet 79 then closes a circuit through the coil of magnet 69. Slow operating magnet 69 then attracts its armature 68 thus breaking the circuit traced above through battery 43 to .znarginal relay 41 and causing relay 41 to release its armatures, resistance 38 preventing the current from battery 37 through magnet 41 from being cient to maintain relay 41 operated. if magnet 69 were not slow operating, then upon the energization of winding 80 and the consequent closing of contacts 118 and 119 and engagement of contact spring 87 with one terminal of magnet 114 (all as described above) magnet 69 might possibly receive current through the armature of magnet 79 before the latter armature left its back contact, and therefore the armature of magnet 69 might possibly be picked up before magnet 7 9 had picked up and released.

The attraction of armature 68 as meneeavro tioned above also closes the energizing circuit for slow operating relay 49 as follows: from ground through battery 43, armature 44, lead 46, armature 64, lead 66, lead 67, armature 68 and n iagne; 49 to ground.

The energization of relay 49 attracts its armature 76 thereby opening the circuit traced above from battery 43 to lead 77.

his opens the circuit traced above through cord bar magnet whereupon a spring (not shown) corresponding to spring 14 of Fig. 4, returns the cord bar 1 to its normal position, but the sets of spring contacts 3 which have been engaged by contacts 4, 4 and 4 of the net bars 2, 2 and 2 remain in such engagement.

The energization of magnet 49 as mentioned above opens the ci cult traced above from battery 43 through magnet 42 at contact spring 48, but closes a circuit for magnet 42 from battery 136 through armature 137, contact spring 48, lead 50, armature 51, lead 52, armature 53, lead 54, contact spring 55, lead 53", magnet 42, lead 58, lead armature 60, lead 62 to ground.

The attraction of armature 76 of relay 49 as mentioned above also causes the operation of marginal line selection control. relay 35, the operating circuit for relay being as follows: from ground through battery 9 43, armature 44, lead 46, armature 64, lead 66, lead 61', lead 74, lead 75, armature 76. lead 137, armature 138 of retarded relay lead 140, magnet 30, lead 33, sleeve conduc' tors of plug 1 and the cooperating jack, lead 34, lead 35 to ground. The purpose in having magnet 49 slow operating is to dela. the closing of the contacts of line selection control relay until after the contacts of line selection control relay 41 are open.

The operation of relay as n'ientioned above and the conserpient attraction of its armatures 7 6 and 142 also causes the opera tion of cord bar magnet 15 over the following circuit: from ground through liiattery 43, armatiu'e 44, lead 46, armature 64, leads 66, 67, 74, 75, armature 76, armature 142. lead 144, armature 145 of relay 56, lead 146. lead 147, magnet 15 to ground. Magnet 15 thereupon operates its cord bar 1 hnd also its arn'iatures 14S and 149.

The function of arm ature 148 will be made apparent hereinafter.

The attraction of armature 149 and the 1 closing of the contacts of line selection con l ll (1 159, lead 160, armature 161, lead 162, armature 163, contact spring 161, pick-up magnet 151 of not bar 2*, lead 165, contact spring 166, armatnres 167 and 90, lead 91, lead 168, lead 169, and armature 170 of line selection control relay to ground.

The attraction o1 armature 11-9 by cord bar magnet 15 an d the closing of the. contacts of line election control relay 35 as mentioned above also cause the energization of net bar pick-up magnet 171 over the following circuit: from battery +13 to conducting member 157 of the cord bar 1, as just traced, thence through spring contact 172, contact 173, conducting member 174, lead 175, armatures 176 and 177, contact spring 178, net bar pickup magnet 171, contact spring 179, armature-s 160 and 100, leads 101, 181, and 182, armature 183 to ground.

'lhe attraction of armature 1 19 by cord bar mag at 15 and the closing 01 the conacts of line selection control relay 35, as mentioned above, also cause the energization of net bar pick-up magnet 18st over the following circuit: from battery 13 to cord bar conducting member 157, as traced above, and thence through spring contact 95, contact projection 186, net bar conducting member 1537, lead 188, armatures 189 and 190, contact spring 191, net bar pick-up magnet 18-1, contact spring 192, armatures 193 and 110, leads 111, 19st and 195, armature 196 to ground.

Upon the energization of a net bar, pickup magnet 151, as mentioned above, net bar is moved to the left as viewed in Fig. 3 to engage a set of its contact projections with a set of spring contacts on the cord bar 1", which is now being held in operated position by cord bar magnet 15. Similarly upon the energization of magnets 171 and 16-1, as mentioned above, the net bars 2 and corresponding to these magnets respectively are moved to the left as viewed in Fig. 0 and a set of contact projections on each of these bars engages a set of spring contacts on the cord bar 1.

The energization of magnet 150, and the energization of pick-up magnet 151 and the consequent operation of net bar 2, all as mentioned above, cause the energization of net bar locking magnet 197 over the following circuit: from battery 4-1, lead 16, armature 6 1-, lead 66, lead 67, lead 7%, lead 75, armature 76, arniatiu'e 112, lead 11 1, lead 198, armature of magnet 15-0, lead 199, lead 200, cord bar conducting member 201, spring contact 202, contact 203, net bar conducting member 20 1, lead 205, magnet 197, armature 16%, magnet 151, armature 166 and 205 to ground. Similarly the energization of magnet 150, and the energization of pick-up magnet 171 and the consequent operation of net bar 2, all as mentioned above, cause the cnergmation o't not bar locking magnet 206 over the following circuit: from battery to cord bar conducting member 201, as net traced, and thence through spring conact 207, contact 208, net bar conducting member 209, lead 210, magnet 206, armature 178, magnet 171, armature 1'79, and lead 211 to ground. Similarly the energization of magnet 150 and the energization of pickup magnet 191- and the consequent ope '1- tion of net bar 2 all as mentioned above, cause the energization of net bar locking magnet 212 over the following circuit: from battery as to cord bar conducting member 201, as traced above, and thence through spring contact 2123, net bar contact 211, net bar conducting member 215, lead 216, magnet 212, armature 191, magnet 184, armature 192, and lead 217 to ground. That part of the circuits traced above for locking magnets 197, 206 and 212 which comprises, lead 198, armature of magnet 150 and lead 199 is shunted by a resistance 218.

T he operation of the pick-up magnet 151, as mentioned above, attracts the armature 163 of the magnet, thereby breaking the in itial operating circuit of the magnet at armature 163. Similarly, the operation of ma nets 171 and 181 break the initial operating circuits of these magnets at armature 177 and 190, respectively. The breale ing of all of these branches of the circuit through magnet 150 causes that magnet to release its armature thereby opening the contact betwen the armature and lead 199 and connecting Winding of retarded relay 139 (instead of lead 199) in parallel with resistance 218 in a circuit supplying current to the locking magnets 197, 206 and 212. Magnet 139 thereupon attracts its armature 138 and thus causes the breaking of the circuit traced above from battery 13 through marginal line selection control relay and thereby causes line selection control relay 35 to rel *ase its armatures. The purpose in making magnet 139 slow operating is to insure that this magnet will not be operated bo'l ore magnet 150 has picked up and released.

The operation of relay 139, as mentioned above, also closes the following energizing circuit for relay 56: from ground through battery 13, arn'iature 11-, lead 46, armature (it, leads 66, 67, 7st, 75, armature 76, lead 137, armature 138, leads 219 and magnet 56 to ground.

Relay 56 then attracts its armature 156 thereby opening the circuit traced above for cord bar magnet 15. The cord bar 1 returns to its normal position. However, the sets of spring contacts of this cord bar which are in engagement with not bar contacts at the time magnet 15 is deenergized, remain in such engagement.

The energization of relay 56, as mentioned above, attracts armature 220 of the relay 1 break at 61 occurs, armature by engaging spring contact 55 connects battery 136 to lead 67, this connection being traceable from battery 136 through elements 1237, 5'18, 50, 51., 52, 53, 54, 5-3, armature to lead 67. Thus, magnets (it) and the pick-up and locking magnets of net bars 2, 2 and 2 magnets 139 and 56, and the pick-up and loc ring magnets of net bars 2, 2? and 2* are maintained energized from battery 136 until the circuit traced above from battery 136 to lead 6'? is broken at armature 51 or by the'deenergization of magnet 36 or 30, due to the removal of plug P or P.

T he breaking of the circuit of magnet 122, as mentioned above, releases its armatures (Set and (55, whereupon the magnets such as 45 and ("31, for other cord circuits such as that containing repeater R, are placed in such condition that any one of them may be operated upon the connection of two lines byone oi 'these other cord circuits.

The selection and connection of the net works for balancing lines L v and L, has now been completed. A network (21) of the type such as networks 21, 22 and 23, is in connection with the transformer windings 22land 222 (at the right-hand end of repeater B, Fig. 1), because the line selection control relay of the line L to which the right-hand plug of repeater R is connected has an armature connected (permanently) to a lead running to the bank of net bar magnets corresponding to the not bars to which networks of the type such as networks 21, 22 and 23 are permanently connected; and a network 2st of the type such as networks 24L and 25 is in connection with these transformer windings because the line selection controlrelay ot the line L, has an armature connected permanently to a lead running to the bank of net bar magnets corresponding to the net bars to which net works of thetype such as networks and 25 are permanently connected; and a network 26 of a certain. type is in connection with these transformer windings because relay 41 has an armature connected (permanently) toa lead runnin to the bank of net bar magnets corresponding to the net bars to which networks of that type are permanently connected. Of course, it line L were of such character that no network of the type of, say, network 2% were required to balance the line, then the armature 10 lof relay ll would be omitted (or, at least, the armature would notbe connected to lead Sal). Thus the lead from the middle armature of the line selection control relay for line L is disconnected from lead 102, there by indicating that line L, is oi such character that it does not require a network of the type of network 2%. The circuit connecting networks 21, 2a and 26 to the transformer windings 221 and 222 at the right-hand end of repeater It may be traced as follows: from winding 221 through lead 223, conducting member 22st of cord bar 1", spring contact 225, contact projection 226, conducting member 227 net bar resistance of network 21, conducting member 280 of net bar 2, spring contact 231, spring contact 232, through a bridging plate to spring contact 283, spring contact 23%, through a bridging plate to spring contact 235, conducting member 236 of cord bar 1", thence to conducting member 2 l1 of cord bar 1 through two parallel branches, one branch extending fron'i conducting" member 236 through spring contact 237, conducting member 238 of net bar 2, network 24, conducting member 239, spring contact 240 to conducting member 2 11, and the other branch extending from conducting member 286 through springcontact 2&2, conducting member 243 of not bar 2 network 26, conductingmember 2 kt, springcontact 2 15, to conducting member 2 11, then from this juncture of the two branches at conducting member'2-tl through lead 24:7 to winding 222. A condenser forming part of the net work 21 is bridged between the midpointof resistance 228 and the midpoint of resistance 2&6.

The circuit connecting networks 22, 25 and 2'? to the transformer windings 2&8 and 2&9 at the left-hand end oi repeater It will not be traced, since itis similar to the circuit just traced.

In order to provide for taking care of an overflow or unusual demand for certain types of balancing networks, lamps such as 250, and are provided to indicate to the operator the type of network required when all 01 the networks of any type which are capable of selection and connection by the cross-bar switch are in use, and lamp such as 253, 25 1, 255 and 256 are provided to indicate to the operator the cord on which the network is required, and variable impedance cord circuits 257, 258 and 259 are provided which the operator can plug into the cord which on 01'? the lamps such to 256 has indicated requiring a balancing network. The operator adjusts the impedance of the circuit such as 257, and 259 to form a network of the type which one of the lamps such as 250 to has indicated is required. 1

The operation 01' the system as regards this feature will now be described on the supposition that all of the networks of the type such, as 21, 22 and 23, except network 23, are in use when the operator inserts plugs P and P into the jacks of lines L and L respectively, as mentioned above.

Then the cross-bar switch and its ass ciated circuits will select and connect to transtormer windings 221 and 222 the network 23, instead of network 21; tor the circuit between lead 8% 111d picl-t-up magnet 80 will be open armature 86 of magnet 8k and the circuit from lead 160 through armatures 1G1 and 1133 to pick-up magnet .51 will he ciri. open at arn'iat ire 1G3. and he, following cnit will be energized .ter onerat' 1Q net tar nil -r.n magnet 260 corresponding to net i "l'ron'i ground ch ong'h battery 4-23,

f' I, I q {3 1 PM r-,' P'r' in 4, til- (in 01, 41, m,

t t i 4 I 3 to, be. at, 1 m, :1 lead am ast me.

eguet iatnre aunature iae net 2550 .ets oi net bar will be similar n circuits ll-IHullzlUiOln) tiacerl in net bar niac n ot' net bars 9. 9, 3,

4, .i ,and 5; and may be trace-a from ground through ha tery 11?. elemen"s ii-E. 1st, 46, G1, on. til". 3 through branch 115 and branch 75, and 135 to lead 116 thence to cord bar conducting member 11?, the spring eontac 'nime-ilia'telv ahove spring: contact 913, the corresponding conducting member of net her 2". the locking; magnet and the pick-up nagnet 260 of net bar 2", the extreme leftcontact spring o't magnet 260, lead ti gromd. et bars 2 and 2 will be operated by means of nick-up circuits through magnets 95 nd 105 and locking circuits through mag-nets and 128 in series. and magnets 105 and 199 in series, all just as hereinbetore described.

Also in the fashion described above, tolne operation of magnet 260 magnet 79 releases, magic; 65) operates, magnet 41 releases. magnet 19 operates. magnet 1536 releases. magnets 35 and 15 operate, and net bars 2 and 2 are operated by means of nick-up circuits through magnets 171 and R2! and locking circuits through magnets 1 1T1 and 2 6 in series and magnets 18st and 212 in series.

However. magnet 150 does not release when armatnres 17'? and 190 of pick-up nag-nets 171 and 18% are attracted, tor

magnet 1.30 remains energized over the following cire iits: from ground through batter e13, elements ist, 16, (it, 66, GT, T l, 5, 7th 1 19" 14 i 145, 144), 152, magnet 150, elements 153, 149, lot, 84-, 155, let-1 15$, 15?, the extreme upper one of spring contacts El which enumerates with net bar 2" the extrezae upper comh 'tin member of not bar if lea-Ll middie aanaturo of magnet 3 .L b, a1 unnure 1.18 (o 11 I LIL! 400.

through the ci uit. just 253;} anl lamp 250 has nrrent from ground mm 250 lamp th .ae net 2G0, left-hand let' eliand armature '4 fin 100 and 169x arma- 1 control relay 35 to e attendant that of the type such 239 id 3 are in use and arr network of such tr i indicates that the on which the auxiiier ad is the cord cerrespoz' icntlant adjusts the iniyemx t. iiWUl'li 257 to term a network o t the i'tqllllill type and inserts plug-s 267 and Satin in i mks L69 and Q70, thereby inerting network 257 in series with the pan allel circuit branches comprising networks 9.? and 2?, and also li .;htin; lamp 271 over a circuit which ll he traced hereinafter,

IA and also breaking at spring contact 2T2 the circuit of magnet The circuit connecting networks 257, 25 and 27 to the t ansformer windings Q48, Sit-5) may be traced as follows: from winding 218 through lead 273. ring conductor of jack 2G9 and plug" 267, right-hand side of network 257. ring conductors of plug 268 and jack 9 0, lead 91h the plate bridging thetwo lower ones oi spring); cent-acts 3 opposite net bar the short-circuiting plate bridging); the t "(0 lower ones of spring; contacts 3, 01- posite net bar 2, the plate bridging; the twolower ones ot spring: contacts 3 opposite not bar 2", to cord bar conducting member 275, thence to cord har conducting; member 278 through two nrallel branches one branch extending from cord bar conducting member 975 through extreme lower spring contact 3 opposite not bar 2. e:-;tren o lower conducting: menil cr of net bar 2, net work 25, contact projection immediately below contact projection 208. spring)- *ontact 3 immediately below contact 207 to cord bar conducting member 276, and the other branch e2:- teudinp; l om cord bar conducting member through extreme lower spring contact 3 opposite net bar 2*. extreme lower conducting member of net bar 2, network 27, contact projection immediately below contact )rojection 214, spring contact in'nnediately JQlOW spring contact 213, to cord bar conlucting member 2T6, then from this juncion of the two branches member 278 through the plate bridging the middle pair of sprii contacts 3 opposite not bar 2*, the plate bridging the middle pair of spring contacts 3" opposite the net bar 2, the plate bridging the middle pair or spring contacts 3 opposite the net bar 2, lead 277', the tip conductor oi jack 2T0 and plug 288, the lefthand side or network 257, the tip conductors of plu and jack 213i lead 278 to trans former winding 24.9.

The circuit orer which lamp 2?1 is lighted,

as mentioneo above, may be traced as follows: from ground, through battery elements 4%, l", 6%, (55, 6'2", 74, 75, 76, 142, 144, through resistance 218 in parallel with the armature of magnet 150, thence through lead 200, the sleeve conductors of jack 270 and plug 271, and lamp 271 to ground. Lamp 271 remains lighted as long as the network 257 is required by the repeater cord corresponding to plug P, but when the connection through repeater R is taiten down, the lamp 271 is extinguished so that the attendant will be advised that plugs 26? and 268 may be removed from jacks and 270.

When the circuit of cord bar magnet 15 is broken at jack contact 272, as mentioned above, that magnet releases, breaking the circuit traced above including armatures H8 and 1&9, magnet 150 and lamp Therefore lamp 253 becomes extinguished. Also, magnet 150 releases, connecting magnet 189 in parallel with resistance 218. Ma 'net 139 then operates, causing magnet to open and extingi'iish lamp 250 and also causing n'iagnct 56 to operate.

The operation of armature 1&5 oi magnet opens a gap in the circuit traced above for cord bar magnet 15, but that circuit has already been broken at jack contact 2'72 as described above. The operation oi armature 220 of magnet 56 breaks the circuit of magnet at contact 55, thus causing the breaking 6 1 of the connection traced above from battery 48, to lead 67. However, 'be- Store this break at (5% occurs, armature 220 by engaging spring contact 55 connects battery 136 to lead 6'7, this connection being traceable from battery 136 through elements 137, 48, 50, 51, 52, 53, 5 55, armature 220 to lead 32". Thus magnets 69 and 49, the pick-up and locking magnets of net bars 2", 2 and 2, magnets 139 and 56, and the pickup and locking magnets of net bars 2 and 2 are n'laintained energized from battery 136 until the circuit traced above from lead 136 to lead 6? is broken at armature 51 or 53 y the decnergization of magnet 36 or 80, .lue to the en'ioval of plug P or P.

The breaking of the circuit of magnet 42,

as mentioned above, and the consequent release of its armatures tie. and ('35 also conditions the magnets such as 4-5 and $1 for op eration upon the connection of two lines by a reymatcr cord other than that of the re peater R.

Gt course, it it had been required that an auxiliary network oi the type such as nc"-- works 21, and 22-3 be connected to trans- .iornier windings 2 1 and 222 instead of to transformer windings 24:8 and 249, then the attendant would have plugz' 'ed the network 257, or some other network of: the same type into jacks 279 and 280 instead of into jacks 2G9 and 2T0.

Networ; is of the same general type as networks 21, 22 and 23; but it it were required that an auxiliary network oi the same general type as networks 2%, 25, 26 and 2? be connected to the transformer windings 24:8) and 2-H), the attendant could adjust the impedance of either of the networks 258 or 259, (or of any one oi? any provided number ct such networks) to form the proper network and plug it into either of the jacks 281 or 282, or into any one oi? any number of such jackswhich might be provided. Or the attendant could adjust the impede cc of the concenser and the lower half of the rcsistances 0t networ; 5? to form a network of the required impedance and insert plug 268 into either of the jacks 281 or 282, leaving plug disengaged from all jacks.

Any desired number of cord l us and repeater cord circuits, and any desired number of net bars with netw rks oil any desired inipedances permanently connected thereto, and any desired nun'iber of auxiliary networks of any desired in'ipedance may be used, the number and character of such elen'ients desired being dependent upon the number and character of the I be nines to interconnected by repeater cords and the volume'ot traiiic over each line.

Although the networks 21 to 2? have been herein referred to as permanently connected to their respectire net bars in oroer to distinguish these netw .rks from the auxiliary networks such as to 259, ano although the networks 21 to 27 appear as permanently connected to their rspective net bars in the diagramn'iatic showing in Fig. 3, it should be understood that the networks to 27 might be arranged to be normally the connected from their respective net bars and be engaged by or connected to the net bars when the latter are operated, without dc parting from this invention. ifhe ilHQi. tion in its broad aspect is not limited to the particular pe of cross-bar switch disclosed herein. In other respects, also the intention is not to be regarded as restricted to the exact arrangement of parts di. l d tor the purpose or explaining the i cntion, since man J changes may be made without departllil ing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. A. repeating ystem comprising transmission lincs, rep i networks for use in balancing means responsire to connecv to said lines tor connecti works to a plurality of at a time, and for connccti in balancing relations to a plural lines, one at a time.

2. A repeating system comprising transmission lines, repeaters theret'er, networks for use in balancing said lines, said nctworks being insullicient to simultaneously balance all 01 said lines which might be simultaneously in connection with said repeaters, and means responsive to connection of said repeaters to said lines for connecting any one of said networks to any one of said repeaters and to any one of a plurality of said lines.

3. A repeating system comprising transmission lines, repeaters, therefor, networks for use in balancing said lines, said networks being insuliicient to simultaneously balance all of said lines which might be simultaneously in connection with said repeaters, and means responsive to connection of said repeaters to said lines for connecting any one of said networks to any one of said repeaters and to any one of a plurality of said lines and for preventing the connection of any one of said networks with one of said lines when said last-mentioned network is connected to any other of said lines.

4. A repeating system comprising transmission lines of Various impedance characteristics, repeaters for said lines, networks for use in balancing said lines, one ot said networks being adapted for use in balancing a plurality of said lines having different inipedance characteristics, one line at a time, means responsive to connection oi said repcaters to said lines for connecting said one network to any one of said plu ality of said lines and to any one of said repeaters. and for insuring that none of said networks is connected to more than one line at a time.

5. A repeating system comprising trans mission lines having Various impedance characteristics, repeaters for said lines, networks for use in balancing said lines, and means responsive to the connection of said repeaters to said lines for connecting any one of said networks in balancing relation to any one of said lines and for connecting any one of said networks to any one of said repeaters.

6. A repeating system con'iprising transmission lines having various impedance characteristics, repeaters for said lines, networks for use in balancing said lines, means responsive to connection at said repeaters to said lines one of said not-- aters, one 1 network if of said for connecting any one of said networks in balancing relation to any one of said lines and for connecting any one of said networks to any one of said repeaters, and for preventing the connection of any one of said networks to more than one line at a time.

'4'. A repeating system comprising transmission lines, a repeater therefor, a plurality of balancing networks having the same impedance characteristics tor use in balancing said lines, and means responsiveto con-- nection of said repeater in one of said lines for selecting and connecting each of said networks to said repeater and in balancing relation to said one line one network at a time.

8. A repeating system comprising trans mission lines having various impedance characteristics, repeaters for said lines, net works of various types for use in balancing said lines, each network being adapted for use in balancing a plurality of said lines having different impedance characteristics and means responsive to connection of said repeaters to said lines for connecting any one of said networks to any one of said lines having various impedance characteristics, and to any one. of said repeaters.

S). A repeating system comprising transmission lines having Various impedance characteristics, repeaters for said lines, networks of various types for use in balancing said lines, each network being adapted for use in balancing a plurality of said lines ha 'ing dillerent impedance characteristics, means responsive to connection of said repeaters to said lines for connecting any one of said networks to any one of said lines having ditlerent impedance characteristics, and to any one of said repeaters, and for preventing the connection of any one of said networks to more than one of said lines at a time.

10. A repeating system comprising transmission lines, repeaters for said lines, a network for use in balancing said lines, and means responsive to connection of said re peaters to said lines for connecting said network to any use of said repeaters and to any one of said lines.

11. A repeating system comprising transmission lines, repeaters for said lines, a network itor use in, balancing said lines, means responsive toconnection of said repeaters to said lines for connecting said network to any one of said repeaters and in balancing relation to any one of said lines and for preventing the connection of said network to more than one of said lines at a time.

12. A repeating system comprising t-'ansmission lines, repeaters therefor, sets of balancing networks suitable for use in balancing said lines, each set comprising networks of various types as regards impedance characteristics, and the number 0t sets. being less than the number of repeaters and than the number of lines, and means responsive to the connection of any one of said repeaters between any two of said lines for selecting and connecting; to each of said two lines suitable ones of said networks for balancing said two lines, whenever such types of: networks are idle.

13. A repeating system comprising trans mission lines having various impedance characteristics, repeaters therefor, net-works having various impedance characteristics for use in balancing said lines, said networks being insutlicient for simultaneously balancing all of said lines which: might be simultaneously in connection with said repeaters, and means responsive to connection 0t any one of said repeaters between any two of said lines for selecting and connecting to each of said two transmission lines suitable ones of said networks for balancing said two lines, whenever such suitable networks are idle.

1+2. A repeating system comprising transmission lines having *arious impedance characteristics, repeaters for said lines, groups oi networks for use in balancing said lines, all of the networks in any one group having the same impedance characteristics and. the networks of different groups having different impedance characteristics, and means responsive to connectioniot said repeaters to said lines for connecting any one of said networks to anyrepeater and to any line.

15. In combination, a transmission line, a balancing network for use in balancing said line, and means comprising a crossbar switch for associating said network with said transmission line.

16. In combination, a transmission line, a. pin 'ality of repeaters, a balancing network for use in balancing said transmission line, and automatic means responsive to the connection of any one of said repeaters with said transn'iission line to associate said network withv the transmission line and said repeater, said means comprising a cross-bar switch.

17. In combination, a transmission line, a repeater therefor, a balancing network for use in balancing said transmission line, and means comprising a cross-bar switch for associating said network with saidrepeater.

18. A repeating system comprising transmission lincs, balancing DQiZWOB TIS 'l Ol' use in balancing said lines, a repeater, and switch ing means comprising a cross-bar switch for associating with said repeater any one of said lines and suitable ones of said net- WQTS to balance said one line.

19. A repeating system comprising transmission, lines, repeaters therefor, balancing networks for use in balancing said lines, and switching means 7 of various typesas re ards imped c comprising a cross-bar than the number of repeaters and than t1 numberof lines, and means responsive to the connect on of any one of said repeaters between any two of said lines for selecting and connecting to each of said two lines suitable ones of said net works for balancing said two lines, whenever such ones of said networks are idle, said means comprising a cross-bar switchhaving pa allcl bars for connection to said networks andha "ing bars intersecting said parallel bars for coi'mecting said parallel bars to-said repeaters 21. A repeating system comprising transmission lines, repeaters therefor, balancing networks for use in balancing said lines, and switching means comprising a cross-bar switch for associating any one of said repeaters with any one of said lines and suitable ones of said networkstor balancing said one line, said cross-bar switch comprising parallel bars for connection to said networ S and bars intersecting said parallel bars for connecting said parallel bars to said re peaters.

22. A repeating system comprising t ansmission lines, a repeater therefor, a series type network and a shunt type netwo k tor use in balancing said lines, and an auroliarr network adjustable to form either a series type network sin'iulating the impedance of said first-mentioned network or a shunt type network simulating the in'ipcdance oi said second-n'ientioned network.

A repeating system comprising 4" mission lines, repeaters therefor, sets of bal- ,ancing networks suitable for use in balancing said lines, each set con'iprising .L acteristics and the number of sets being than the number of repeaters and than the numberof lines, means responsive to the connection of any one of said repeaters between any two ofsaid lines tor-selcctiiu ed connecting to each of said two line: ones of said networks for balanr" lines, whenever such ones of are idle, and an auxiliary network adj: itable tosimulate different types of said l il'bt" mentioned networks, for connection to one of said two lines when said suitable ones of said first-mentioned net-works are not available.

24-. A transmission system comprising transmission lines, link circuits for inter connecting said lines, networks of different types tor use in balancing said lines, and means responsive to the interconnection of two of said lines by said link circuits for indicating a type of network required for use in balancing one oi said lines and for indicating the link circuit on which such network is required.

A. tra smission system comprising transmission lines, link ircuits for interconnecting said lines, networks of diti'erent types suitable for use in balancing said lines, and means responsive to connection of two of said lines by ,rid link circuits for indicating a type network required -for use in balancing said connec ed lines.

2%). A repeating system comprising transmission lines, repeaters therefor, link circuits for connecting said repeaters between said lines, sets ott' balancing networks suitable for use in balancing said lines, each set comprising networks of various types as regards impedance characteristics and the niiniber of sets being less than the number or repeaters and than the number of lines, auxiliary networks sin'iulating the impedances of some of said iilf-iiT.tGIlilODQ(l networks for connection to said lines when suitable ones or said first-mentioned networks are not available, and means responsive to the connection of any one of said repeaters be tween any two of said lines for selecting and connecting to each of said two lines suitable ones at said first-mentioned networks to balance said two lines, whenever such ones of said first-mentioned networks are idle, and for indicating to an attendant whenever such ones of said tirst-n'ientioned networks are not idle, the types of auxiliary networks required and the link circuits on which each is required.

27. A repeating system comprising trans mission lines, repeaters therefor, link circuits for connecting said repeaters between said lines, sets of balancing networks suitable for use in balancing said lines, each set comprising networks of various types as re ards impedance characteristics and the number of sets being less than the number of repeaters and than the number of lines, auxiliary networks simulating the impcdances at some o't said first-mentioned networks, for connection to said lines when suitable ones of said first-mentioned networks are not avaiable, means responsive to the connection of any one of said repeaters between any two of said lines for selecting and connecting to each of said two lines suitable ones ct said first mentioned networks to balance said two lines, whenever such ones or said first-mentioned networrs are idle, and for indicating whenever such one of said first-mentioned networks are not idle, the type o1 auxiliary IlQtWOI lZn required and the link circuits on which each is required, and means for indicating when a repeater to which an auxiliary network has been con nc-cted is disconnected from said lines.

28. A transmission system comprising transmission lines, link circuits for interconnecting said lines, networks of different impedance characteristics for use in balancing said lines, means responsive to interconnection of two of said lines by said link circuits for indicating a type of network required for use in balancing one of said lines and for indicating the link circuit on which such network is required, and means for indicating when a link circuit to which such network has been connected is disconnected from said lines.

29. A transmission system comprising transmission lines, link circuits for interconnecting said lines, networks 01" different impedance characteristics for use in balancing said lines, means comprising a crossbar switch responsive to interconnection of two of said lines by said link circuits for indicating a type of network required for use in balancing one of said lines and for indicating the link circuit on which such network is required, and means for indicating when a link circuit to which such network has been connected is disconnected from said lines.

230. The method of connecting balancing networks to lines having various impedance characteristics and to repeaters for the lines, which comprises connecting one of the networks to a plurality of the repeaters, one repeater at a time, and connecting said network in balancing relation to a plurality of the lines one line at a time.

31. The method of connecting balancing networks to lines having various impedance characteristics and to repeaters for the lines, which comprises connecting one of the networks to one of the repeaters in response to connection of said repeater to certain of the lines, connecting said network to said repeatcr in response to connection of said repeater to others of the lines, and connecting said network to another repeater in rospouse to connection of said other repeater to certain of the lines.

The method of connecting balancing networks to lines having various impedance characteristics and to repeaters for the lines, which comprises connecting one of the networks to one of the lines in response to con nection of one of the repeaters to said line, and connecting said network to another of the lines in response to connection of another repeater to said other line.

33. A repeating system comprising transmission lines, repeaters therefor, networks for use in balancing said lines, said networks being insutticicnt to simultaneously balance all of said lines, which might be simultaneously in connection with said repeaters, and means for connecting any one of said networks to any of said repeaters and to vany one of aplurality of said lines.

34. A repeating system comprising transmission lines, repeaters therefor, network for use in belencingsaid lines, said networks being insutlicient to simultaneously balance all of said lines which might be sinmltaneously in connection with said repeaters, and means for connecting any one of said ,net

Works to any one of said repeaters and to any one of a plurality of said lines and'for insuring that none of said networks willbe in connection with more than one line at a time.

In Witness whereof, I hereunto subscribe my name this 25th day of November A. 1).,

ROY 1). CONWAY. 

